alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (MICROPSIA CnC Domain)"; flow:from_server,established; tls.cert_subject; content:"CN=new.young-spencer.com"; fast_pattern; reference:md5,738b3370230bd3168a97a7171d17ed64; reference:url,docs.google.com/document/d/1oYX3uN6KxIX_StzTH0s0yFNNoHDnV8VgmVqU5WoeErc; classtype:domain-c2; sid:2025918; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2018_07_27, deployment Perimeter, malware_family MICROPSIA, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_30, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)